--  @testpoint:opengauss关键字begin(非保留)，作为函数名
--关键字不带引号-成功
drop function if exists begin;
create function begin(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function begin;

--关键字带双引号-成功
drop function if exists "begin";
create function "begin"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function "begin";

--关键字带单引号-合理报错
drop function if exists 'begin';
create function 'begin'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/

--关键字带反引号-合理报错
drop function if exists `begin`;
create function `begin`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/